Protective mechanism for safe-doors



(No Model.)

A. B. CURTIS. PROTECTIVE MECHANISM FOR SAFE DOORS.

No. 596,294. Patented Dec, 28,1897.

, J 'y-J. T w? NlTED STATES ATENT @rrrcn,

PROTECTIVE MECHANISM FOR SAFE-DOORS.

SPECIFICATION forming part of Letters Patent No. 596,294, dated December 28, 1897.

Application filed July 17,1897. Serial No! 644,904. (llo'modeL) To aZZ whom it may concern:

Be it known that I, ARTHUR B. CURTIS, of Revere, county of Suffolk, State of Massachusetts, have invented an Improvement in Protective Mechanism for Safe-Doors, of which the following description, in connection with the accompanying drawin gs,is a specification, like letters and figures on the drawings representing like parts.

This invention has for its object the production of simple and efiective means for preventing the unlocking of safe or vault doors by burglars before or after the bolt-controlling mechanism has been tampered with or destroyed- In apparatus of this character as now constructed the bolts are thrown by suitable means and are held in looking position by mechanism mounted on the inner side of the door, and it may be a time or combination lock, or both. If the locked door can be drilled in order to insert an explosive, the bolt-controlling mechanism may be so shattered as to permit the ready withdrawal of the bolts and subsequent unlocking of the door.

Electricity has been employed by burglars to assist them in their work by making an electric are between the safe-door and electrode in circuit with-a trolley or lamp system, and it has been found that by the are an opening will be quickly formed. in the hardest steel through which an explosive can readily be inserted. A flame of very high temperature can also melt a hole in such doors. In my present invention I have overcome the effect of such tampering with safe-door mechanism by providing one or more dogging devices adapted to at times cooperate with and hold the locking-bolt from withdrawal, the dogging device being held normally inoperative by a thermostatic controlling device which upon a rise in temperature of the door will release the dogging device and permit it to move into engagement with the bolt. Therefore even should the usual time or combination lock mechanism for the bolt be blown off the bolts will be automatically held by independent means from being withdrawn and the entrance to the safe or vault is guarded as safely as before it was tampered with.

Figure 1 is a sufficient portion of the inn er side of a vault'or safe door to be understood, with locking mechanism applied thereto and showing one embodiment of my invention; and Fig. 2 is an enlarged sectional view taken on the line 0000, Fig. 1, and showing one of the dogging devices.

The door A, the sliding locking-bolts B B, connected by a cross-bar B and actuated in any suitable manneras by a handle B having fast thereon a rocker-arm B connected with the cross-bar by a slot-and-pin connectionthe detent-arms b I), connected with the bolts and cooperating with the locking mechanism L to prevent withdrawal of the bolts from their seats in the side wall A of the vault or safe, are and may be of any usual or suitable construction in apparatus of this class.

On the inner side of the door I have shown a series of independent dogging devices D D to cooperate, respectively, with the bolts B B. As herein shown, each dog comprises a shank d, having one end bent outwardly, as at d, to enter a suitable notch, as 3, in the adja cent bolt when the dog is moved into operative position. Suitable guides d retain the dogs in position and guide them in their movements, the dogs being herein shown as gravity-actuated, although it will be obvious that a spring could be substituted for gravity, as shown, for instance, at S in dotted lines, Fig.1.

It will be observed that the dogs are entirely independent of each other and theusual bolt-controlling mechanism L, and said dogs are held normally in inoperative position by a thermostatic controlling device. This controlling device may be a step, as c, Fig. 2, of readily-fusible material at a comparatively low temperature attached to the inner surface of the door A below the lower end of the dog, holding the latter out of engagement with its bolt. WVhen the door is heated, as it would be by the electric method of boring hereinbefore referred to, the rise in temperature would cause the controlling device to melt and release the dog, which would immediately come into engagement with the adjacent bolt and hold it from movement. Should the locking mechanism L be thereafter blown off, it will be obvious that the bolt would still be held from withdrawal by the dogging device.

It is obvious that the thermostatic controlling device can be arranged in various Ways, for the fusible material might be inserted in 2 scenes sheet form between the door and the back of the usual bolt-controlling mechanism, retaining the dogging devices normally in inoperative position, and my invention is not restricted to the particular manner of applying the fusible materiahnor to any particular form of controlling device, for, so far as I am aware, it is broadly new to provide independent dogging devices for the bolts, said normally inoperative devices being rendered operative by the generation of an unusual or abnormal amount of heat in or on the safe or vault door.

I prefer to employ a plurality of dogs for each bolt, as thereby the dogs are distributed over a greater portion of the door, and are thus apt to be nearer the heat applied to the door, so that the action of the dogs will be more rapid.

My invention is particularly adapted for use in connection with the modern hardenedsteel safe or vault doors employed in banking and similar institutions.

Having fully described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In an apparatus of the class described, locking mechanism including a bolt, a dog to cooperate at times with and prevent witl1- drawal of the bolt, and means to normally retain the dog from engagement with the bolt, said means being made effective to release the dog upon an abnormal rise in temperature of the apparatus adjacent the locking mechism.

2. In an apparatus of the class described, a bolt, mechanism to operate it, a gravity-dog independent of SilldlllOClliLlllSlll adapted to move into engagement with and prevent withdrawal of the bolt, and detaining means for said dog, operative to release it upon a rise in temperature of the adjacent parts, substantially as described.

3. A safedoor, a lockingbolt and controlling mechanism therefor, one or more independent dogs on the inner side of the door, adapted to engage and prevent withdrawal of the bolt, and a readily-fusible detaining device to normally hold each dog inoperative, whereby a rise in temperature melts said device to permit the dog to move into operative position, substantially as described.

4.. In an apparatus of the class described, locking mechanism, and normally inoperative means, rendered operative by an abnormal rise in temperature of the apparatus adjacent thereto, to prevent unlocking of said mechanism, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ARTHUR l CURTIS.

Witnesses:

JOHN C. EDWARDS, AUGUSTA E. DEAN. 

